Sectional shaft



`Fame M, T949., M. EssL SEQTIONAL SHAFT Filed May g4, 1944 Mar 5567/.

HTT R/VEY Patented June 14, 1949 SECTIONAL SHAFT Max Essl, Swarthmore, Pa., assignor to William H. Harman Corporation, Wilmington, Del., a

corporation of Delaware Application May 24, 1944, Serial No. 537,156

The invention relates to a sectional shaft and is directed particularly to an improved cam shaft for use in internal combustion engines and to the manufacture of the same.

In the construction of internal combustion en-` gines it is common to completely enclose the cam shaft within the engine block or casting, and it has been found desirable to design the engines in such a manner that the cam shaft may be removed and replaced with a minimum of disturbance of the other parts of the engine. In large modern engines, particularly those of the Diesel type, the cam shafts are sometimes of such a length that insufficient space is available to permit endwise movement thereof for removal or replacement. It has also been recognized that the arrangement of the cam shaft and the manner of supporting it should be such that the engine structure is not undesirably weakened where provision is made for the removal of the shaft transversely through openings in the side of the engine.

In order to meet these requirements attempts have heretofore been made to provide a sectional cam shaft so designed that the individual units may be removed transversely from the engine through comparatively small openings. So far as I am aware, however, these attempts have been confined to sectional shafts the units of which are provided with coupling flanges which are bolted together When the shaft is assembled, or to sectional shafts the units of which are provided on their ends with external and internal gear teeth such as utilized with the cam shaft disclosed in Patent No. 2,323,209, granted June 29, 1943, on an application filed by me.

Sectional cam shafts of the type wherein the separate units are connected together by means of coupling flanges and bolts are not only expensive to manufacture, but the coupling elements require an undue amount of space both transversely and lengthwise of the shafts, and the 1ocation of the bolts is such that they are not readily accessible in assembling and dismantling the shafts. Sectional Cam shafts which utilize coupling and driving members in the form of internal and external gear teeth are also expensive to manufacture, the coupling elements take up an undue amount of space longitudinally of the shaft, and such a shaft requires a thrust bearing for each shaft section when the shaft is assembled in the engine.

One of the principal objects of the present improvement is the provision of a cam shaft or the like which consists of standardized or identical units which may be assembled end to end in order to form a shaft of any desired length as well as a shaft having individual units which may be removed or replaced transversely of the shaft with a minimum of disturbance of the other elements of the shaft and the parts associated therewith.

7 Claims. (Cl. 'Z4- 568) Another object of the invention is the provision of a cam shaft or the like which consists solely of a tie member and separate integral units each of which may be adjusted independently about the axis of the shaft in order to adapt the separate units as well as the entire shaft to any cylinder and crank arrangement and ring order of the engine. A still further object of the invention is the provision, in a cam shaft, of individual sections, one for each cylinder of the engine, so designed that they may be uncoupled or dismantled with a minimum of longitudinal movement, and so that an individual section may be readily removed or replaced from the side of the engine, through a comparatively small opening, Another object of the invention is the provision, in a sectional cam shaft or the like, of coupling means which is comparatively inexpensive to manufacture and requires substantially no space transversely or longitudinally of the shaft. A still further object of the invention is the provision, in a cam shaft or the like, of coupling means which serves to center and align the sections of the shaft accurately with respect to each other and provide a simple driving connection between the sections. It is also an object of the invention to provide for a sectional cam shaft or the like a jointed or ilexible tie member or retaining means which extends through the shaft sections for holding them together, and which is so constructed that it may be easily removed endwise from the shaft or engine through a space which is so restricted as to prevent the removal and replacement of a rigid tie rod. Still other objects and advantages of the improvement will be apparent from the following description, taken with the accompanyingr drawing, wherein:

Fig 1 is a side elevational View of a sectional cam shaft having one form of the present improvement incorporated therein;

Fig. 2 is an enlarged view of the right hand end of the cam shaft shown in Fig. 1, with parts cut away to show details of construction;

Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a transverse sectional view taken on the line 4--4 of Fig. 2 and showing the arrangement of the radial serrations which join the shaft sections together;

Fig. 5 is a side elevational view of a portion of a cam shaft provided with a slightly modified form of coupling means, parts being in section to show details of construction;

Fig. 6 is an end elevational view of a portion of one of the cam shaft sections shown in Fig 5; and

Fig. 7 is a detailed sectional view of the modified form of coupling means shown in Figs. 5 and 6.

While the present improvement may be utilized hollow end cap or thrust member II on one 1 end thereof and a hollow driving section I2 on the opposite end. Each of the identical-'"sections I0 is provided with a bearing surface I3 by means of which it is rotatably supportedon someslit'able part of the engine, and with a pluraltypf camsm I4 for actuating various moving parts of the engine, such as a fuel pumptandlf'intakaand.exhaust valves, in a manner well understood.

The end of each of the identical sections'is provided with a plurality of radial serrations I5 iwhich inter't with'. similar radial serrations f on 'lthe Vends'A oiadjoining sections in v"order to"l propf A'erlycenter thefsection-s with respect to cache other iiandprovidefafdriving c'onnec'tionl between the fse'ctions when `the shaftfis assembled. "'The'fend f,-

cap `I I and the" driving .section 'I2 l'are' alsopro- A'vided with radial serrations'tolinterfitlwththe ''serrations'fon' the :endsofthe identical Isections adjacentthereto The driving section JI Zmay Ibe vprovided'witha bearing surface -IIfor rotatably supporting this'-se`ction ona 'suitable part of the-engine, andithis section -isf'pr'eferably pro- -which axed' thrust lelement TI8fis received' to .preve'nt endvvise movement' vof ythe shaftlwhen'; `assembled inthe engine. '-:Rotary motion may be given' tothe sha'ft through agearla'securdto the outer 'ruff 'I1' by meansloffbolts 'Eiland driven in any suitable manner intim'ed rel'ation''to'the crank vshaft of the engine.

"The varioussections of the shaft'are 'held .ftogether rigidly by means of a'jointd' lorfiexible tievv member v2 I extending throughout '-the'fien'g'th Vof the 'shaft in the opening' "221formed AVby the aligned bores 'of vthe individual sections. *While l' other forms of tie member maybe employedisu'ch `as ajointed rod or ail-flexible cable;1v as'illustrated "inthe drawing, the tiemember is in the form'of a roller 'chain made upv of inner links 23, outer 'fli-nks 24,' and pins 25 connectingfthe' loverlapping portions of the inner and'outer' links. 'The links on the opposite sides of the chainare'spacedfrom "each other on'the pins 25 byfsuitable' rollers or spacing sleevestv 26. Thetransverse dimensions of the vlchain areprefera'bly'such thatthelinks-A contact with the surface 'of the hereof-'the shaft sections as shown in Fig. 3 in order' ftoyprevent -'-'transverse `vibrational movement of f the' tie "mernben Each end of the"'chain'is preferablysecmed'toa-55 fra 'block '2 `which`` ts 'within thetbore'of the lshaft iin 'the manner illustrated-in Figs 2,1 3 and" 4. The block 21"sh0wnin Figi 2 is provided with a produced `threaded-extension" "28 "projecting -outwardly through a central 'opening '29inltheend "*capl I'to'receive a lock n'ut 3u thereon. The' nut "530 lengages'fwith'endl cap'lll When'tthe parts .of the shaft are lassembled. y'The' reduced extensionvi 3| on the opposite end of the chain/'projects outwardly'f'through the drivinggear "'I9"and.is'v like riviseprovided with a 'threaded vlock nut 32 which lengages' 'vvithfthe -gear I 9' inorder vto-"apply pressure to the driving sectionor end Ithrust member "l 2 and thereby* clamp'the 'sections .of the' "shaft "rigidly together' 'whenthe' 'nutsVA 30""and32 are`- tightened.

HThe `varioussecti'ons oi they shaft are preferably made from" forgedtst'ock. `f 'In 'theinm'anufaetme the. iorgings are rough bored to provide a central opening' therethrough; afterwhicn `the cams and" bearings may be rough ground or machined. The bore may then be ninshed and the ends of .thefsections provided with finished-surfaces perpendicular to the axis of ithe bore. "The sections are then suitably centered in a heavy press and the radial serrations I5 are impressed on the end ".surfa'ces The sections are then centered on the serrated ends during the operation of finish i grinding the earns'Y and bearings.

4"'When'the shaft sections are made in this manner,` the radialY serrations I5 serve to center the `:sections accurately and align them properly with respect to one another when they are assembled 'inthe shaft and the nuts 30 and 32 on the opposite ends of the tie member 2I are tightened to `lthe desired extent against the lendthrust mem- L bers `I I; and 'I 2. The radial.:serrationsl also'serve -to yprovide the necessarydriving: vconnectionbbetween the sections of theishaftfwithout .taking up any space longitudinallyfofthe: shaft-and "without vextending transversely `fbeyond the :periphery of rthe shaft proper.

In the operation l of impressing fthe radiall'fserrations. in the ends of thefshaft sectionsit mayfbe desirable, vunder certain conditions,'=to 4provide some means wherebytheifiow of the-:metal trans- Jversely of the sections .may4 be facilitated. simple means for accomplishing'this is illustrated in'fFigsL 5,` 6 and 7,' and involves theprovision of an' annular groove 33 inf each endz'offfthe'sections. L'Inthis case the radial fserration's 34 areimpressed only ron the portion' of the end surface/inwardly ofthe groove'33,.the surface 35y outwardly ofthe `-groove beingleft free "oiserrations lso"'that"it. may "abut against the correspondingsurface on lthe -fendof an adjacent section. `:In thismanneritis 1:sometimes'possiblev to secure a rnoreil accurate :alignment of thewshait sectionsllthan Acouldbe a obtained vlwhere the' serrationsi lextend .entirely across the end surface 'of'theshaft sections. -'It "-willi be understood,v of 'coursegithat the procedure followed in making ashaft sectionhaving'fthis modified form" of coupling. .means'f will"V be `substantially the 'same as that described above ex- `-cept 'for thewadditional' operation lwhich fisfrequiredinproviding the annular'.groove'- 33 inthe f1 ends of'lthe shaft sections.

vFrom-the above' description'ofthe improvement it i will be apparent thatthe separate-fsectionsbf the cam shaft may be readily inserted l'through "fsuitableopenings in the' side'- off the 'engine and f positioned in their respective bearingswith/the radial serrations on'lthe'ends of 4thevsections interi fitting with the serrations on the ends of adjacent sections rIt-v`ill also"be apparentthat each' of `v'the separate sections-may'be'isuitably adjusted ""abo'utthe axis oithe shaft-independently of the -otloerfsections in order to provide the desired timing arrangement of the cams. vWhen the 01 sections are thus assembled inffend to end'relation in the engine, the Iflexiblev tie-member may "be inserted through the lassembled"sections from ltheendof the engine. Dueto thefiexibility'or rvjointed construction of the tie 'memben it'm'ay "be readily inserted or removed from'theend' bf the engine notwithstanding Ythe/lackA 'of 'sufficient `space to'permit the'in'ser'tion and removal 'of a 'rigid shaft or'tie rod.

Adjustment of the cams maybe easily effected 0 at Aany time by merely loosening the clamping Vnuts on the lends' of the tie member sufficiently .to permit disengagement oilthe serrations on'the ends of the section to be adjustedsothat it may be moved angularlyiinto thelposition desired. 5'The 'clamping' nutsmay then'be tightened to clamp the sections of the shaft together and restore its rigidity. The size of the teeth on the ends of the sections should be such as to provide the range and degree of adjustment desired. While the forms of the improvement illustrated in the drawing show serrations extending entirely around the end of the sections, it will be understood that the arrangement of the serrations may be discontinuous, that is, they may be arranged in suitable groups so long as they perform the intended function. It will also be apparent that the use of identical sections makes it possible to build up a shaft of any length for use in engines having any number of cylinders.

While a preferred form of the improvement has been disclosed, together With a modification of the coupling means, it is to be understood that the invention is not limited to the precise structure or manufacturing procedure disclosed herein.

For example, the number of cams and bearings on each shaft section may be varied as desired, and the sections may be of any suitable formation other than cylindrical. Also other forms of tie member may be used so long as they are capable of being bent laterally for insertion into and removal from the shaft sections, or are formed of jointed sections capable of being readily assembled and disassembled. The above description and the accompanying drawings are therefore to be regarded as illustrative only, and it is to be understood that the invention is susceptible of other forms and arrangements so long as they come within the scope of the appended claims.

What I desire to claim is:

1. A power transmitting shaft comprising a plurality of hollow sections arranged in end to end relation and having motion transmitting elements thereon, cooperating means on the adjacent ends of adjoining sections for centering and aligning the sections with respect to each other and providing an adjustable driving connection between the sections, a ilexible tie member extending through said sections, and means on said tie member for clamping said sections rigidly together.

2. A cam shaft comprising a plurality of hollow sections arranged in end to end relation and having cam elements thereon, cooperating means on the adjacent ends of adjoining sections for centering and aligning the sections with respect to each other and providing an adjustable driving connection between the sections, a flexible tie member extending through said sections, and means on said tie member for clamping said sections rigidly together.

3. A cam shaft comprising a plurality of hollow sections arranged in end to end relation and having cam elements thereon, a plurality of serrations extending radially on the ends of each section and arranged to intert with the serrations of an adjoining section to provide centering and aligning means and an adjustable driving connection between said sections, a flexible tie member extending through said sections, and means on the ends of said tie member for clamping said sections rigidly together.

4. A cam shaft comprising a plurality of hollow cylindrical sections having a bearing memberl and a plurality of cam elements on each, a plurality of serrations extending radially on the ends of each section and arranged to interiit with the serrations of an adjoining section to provide centering and aligning means and an adjustable driving connection between said sections, a tie member extending through said sections, and means on said tie member for clamping said sections rigidly together.

5. A cam shaft comprising a plurality of hollow cylindrical sections having a bearing member and a plurality of cam elements on each, a plurality of serrations extending radially on the ends of each section and arranged to interiit with the serrations of an adjoining section to provide aligning means and an adjustable driving connection between said sections, a thrust member on the outer end of each end section and having radial serrations thereon intertting with the serrations on the end sections, a jointed tie member extending through said sections and said thrust members, means on said tie member for applying pressure to said thrust members to clamp said sections rigidly together, and means on one of said thrust members for rotating said shaft.

6. A sectional shaft comprising a plurality of hollow sections arranged in end to end relation, a plurality of serrations extending radially on the ends or" each section and arranged to intert with the serrations of an adjoining section to provide centering and aligning means and an adjustable driving connection between said sections, a, ilexible tie member extending through said sections, and means on the ends of said tie member for clamping said sections rigidly together.

7. A sectional shaft comprising a plurality of hollow sections arranged in end to end relation, a plurality of serrations extending radially on the ends of each section and arranged to interiit with the serrations of an adjoining section to provide centering and aligning means and an adjustable driving connection between said sections, a thrust member on the outer end of each end section and having radial serrations thereon intertting with the serrations on the end sections, a. flexible tie member extending through said sections and said thrust members, and means on said tie member for applying pressure to said thrust members to clamp said sections rigidly together.

MAX ESSL.

REFERENCES CITED The following referefnlces are of record in the file of this patent:

UNTED STATES PATENTS Number Name Date 351,118 Chadwich Apr. 23, 1907 933,285 Blair Sept. 7, 1909 1,483,499 Allee Feb. 12, 1924 1,580,173 Talbot Apr. 13, 1926 1,977,194 Malkovsky Oct. 16, 1934 2,202,330 Brock et al May 28, 1940 2,291,709 Goetze Aug. 4, 1942 2,402,868 Boyle June 25, 1946 FOREIGN PATENTS Number Country Date 91,944 Germany June 25, 1898 78,575 Switzerland Aug. l, 1918 

